The invention is concerned with a sound or probe for the determination of the internal measurements of hollow organs and hollow parts of the body, such as in a human, especially such which can only be reached by means of sounds which have a small cross-section, as for example, the uterine cavity.
The uterine cavity varies in size according to the individual, depending for example on age, the number of previous pregnancies and childbirths, and the intake of various hormonal preparations which are, for example, used for the treatment of dysfunctional bleeding, corpus luteum insufficiencies, endometriosis, uterine hypoplasia, myomas and also as oral contraceptives.
The measurement of the uterine cavity occurs thus far with the aid of sounds, the graduated scale of which makes it possible to determine the distance between the orifice of the uterus and the fundus, in the longitudinal direction. These sounds further serve to probe out the side walls of the uterus.
Other measures such as bi-manual palpation give a subjective estimate of the size and position of the organ. A contrast x-ray of the uterine cavity is possible with hysterosalpingography. This system is of limited use for genetic and fertility risk reasons.
The determination of changes in the interior of the uterus while under hormonal therapy, as for example, for the prevention of hypoplasia with resulting reduction in fertility, cannot be adequately performed by means of the described methods. The measurement of the uterine axis does not permit one to draw any conclusion regarding the overall change in the uterine cavity. The evaluation of this measure by itself can, in certain circumstances, lead to a false representation of the structure of the uterine cavity. The use of intra-uterine contraceptives or pessaries has shown a series of adverse effects, including metrorrhagia, endometritis, gradual perforations of the uterine wall, intracavity and ectopic pregnancies, as well as multiple laborlike contractions of the uterus which, based on experience, can be traced back to a dimensional incompatibility between the uterine cavity and the pessary. The measurement of the uterine cavity, especially the transverse measurement, i.e. the distance between both internal tubular os, is therefore a prerequisite for the use of fitted intrauterine pessaries.